One of the sites we host received an unusually large amount of requests (through a Reddit post that got upvoted a lot). We had to update our caching setup as well as create an additional load balancer to deal with the amount of requests.

We have contacted our storage backend provider and will keep you updated as soon as we learn more about the situation. So far we have replaced a load balancer, but are still seeing a large number of 504 responses from the backend as well as 404s